The present invention relates to the automatic transportation, processing and measurement of the chemiluminescence and bioluminescence of substances.
Bioluminescence and chemiluminescence have been applied for various types of measurements of substances (Gorus, F. and E. Schram. Clin. Chem. 25: 512-5, 1979), viability of cells (Tarkkanen, P., R. Driesch and H. Greiling. Fresenius Z. Anal. Chem. 290: 180-181, 1978) and as a means for the quantification of antigen-antibody complexes (Velan, B. and M. Halmann. Immonu Chemistry 15:331-33,1978).
Normally the bio- and chemiluminescence measurements are carried out in manually operated instruments, although flow-through systems have been applied for purposes of automation. A segmented flow-through system applies air bubbles to separate samples and to mix samples with reagents (Johnston, H.H., C.J. Mitchell and G.D.W. Curtis, pp.210-214, In Rapid Methods and Automation in Microbiology (H.H. Johnston and S.W.B. Newsom, Eds.); Learned Information (Europe) Ltd., Oxford, 1976), while in so-called Flow Injection Analysis (FIA) the homogeneous samples move in capillaries. Certain nonhomogenous samples, such as cell samples, biological fluids (blood, urine, milk) are not easily applicable to a flow-through system because of problems associated with precipitation of cells, proteins, fat globules and other particles in the tubes and capillaries. Therefore, the measurement of such samples is more reliable when the samples are handled discretely in individual containers through all steps in the analyzing procedure.
Automatic luminescence measurement of discrete samples has been possible with a liquid scintillation counter by applying special modification to provide automatic reagent dispensing (see Hammerstedt, R.H. Anal. Biochem. 52:449-455, 1973) or in an instrument applying a light-transparent filter for carrying samples and reagents.
Liquid scintillation counters (LSC) are expensive, voluminous and not-optimal for luminescence measurements. The most important draw-backs of a liquid scintillation counter are that the sample size is large (from 2-10 ml), dynamic range is only 2-3 decades and there is a 20 second delay before the sample goes from the transport mechanism ot the measuring position. Furthermore, these counters are difficult to apply for automatic sample processing as automatic injection of reagents and incubation at a given temperature cannot be accomplished without significant changes in the original construction.
An instrument using a light-transparent filter disclosed in U.S. Pat. No. 3,940,250 is meant only for samples to be filtered and its use is limited to small sample and reagent volumes only. Furthermore, it can be used only for one analysis at a time.
It is, therefore, an object of the present invention to provide a method and apparatus for measuring of samples by luminescence which will overcome the above disadvantages.